Gas water heater and control method thereof

Abstract

The embodiment of the invention provides a gas water heater and a control method of the gas water heater. The gas water heater comprises a water path. The flow meter is arranged on the water path; the combustor is used for heating water flow in the water path; the fuel gas pipeline is used for conveying fuel gas to the combustor, and a fuel gas adjusting valve is arranged on the fuel gas pipeline; the controller is used for determining the flow change amplitude of the water flow according to a flow signal from the flow meter and controlling the booster pump and the gas adjusting valve according to the flow change amplitude so as to control the gas water heater to start a waterfall washing mode, the booster pump is used for being connected with a water path, and when the gas water heater works in the waterfall washing mode, the booster pump is used for being connected with the water path. The booster pump enables the output water flow of the gas water heater to be larger than the rated water flow. According to the technical scheme, the waterfall washing mode is started more conveniently and safely. In addition, no matter how many water using ends are connected to the water path of the gas water heater, the waterfall washing mode can be accurately started at one water using end.

Description

Technical Field

[0001] The present invention relates to the technical field of water heaters, and in particular, to a gas water heater and a control method thereof. Background Art

[0002] With the development of the times, people's requirements for bathing are getting higher and higher. Water heaters for bathing can be divided into electric water heaters, gas water heaters, solar water heaters, etc. according to different energy sources. They can also be divided into instant water heaters and storage water heaters according to the heating method.

[0003] A gas water heater includes a water circuit, a gas pipeline, and a burner. The gas pipeline is connected to the burner and is used to supply gas to the burner. A gas regulating valve may be provided on the gas pipeline to regulate the gas flow rate in the gas pipeline. The water in the water circuit is heated by burning gas in the burner. In a usage scenario such as a household, generally, the gas water heater is installed in the kitchen as close as possible to the municipal gas pipeline in the home, while the user takes a bath in the bathroom. Therefore, the user needs to leave the bathroom and come to the kitchen to change the working conditions of the gas water heater. Some gas water heaters are provided with a communication device. Through this communication device, the user can remotely control the switching of the working mode of the gas water heater through a smart device such as a mobile phone.

[0004] Although the remote control based on the communication device brings certain convenience, it requires the user to operate the mobile phone during bathing. This is not only inconvenient to operate, but also easy to damage the mobile phone, and is very inconvenient for the elderly and children, resulting in poor user experience. Summary of the Invention

[0005] In order to at least partially solve the problems existing in the prior art, according to one aspect of the present invention, there is provided a gas water heater, including: a water circuit; a flow meter provided on the water circuit; a burner for heating the water flow in the water circuit; a gas pipeline for supplying gas to the burner, with a gas regulating valve provided on the gas pipeline; and a controller for determining the flow rate change amplitude of the water flow according to the flow signal from the flow meter, and controlling a booster pump and the gas regulating valve according to the flow rate change amplitude to control the gas water heater to turn on the waterfall washing mode, wherein the booster pump is used to connect to the water circuit, and when the gas water heater operates in the waterfall washing mode, the booster pump makes the output water flow rate of the gas water heater greater than the rated water flow rate.

[0006] The above technical solution can conveniently provide hot water with a flow rate greater than the rated water flow rate for users, significantly improving the bathing experience of users. Compared with controlling a gas water heater through other remote control devices or intelligent devices, the above operation is more convenient, safer, and has higher reliability. In addition, regardless of the number of water-using ends connected to the water path of the gas water heater, during the water intake process, the flow rate change range of the water flow can reach a specific characteristic by opening and closing any water-using end, and the waterfall washing mode can be turned on. This solution is applicable to occasions where multiple people use water, and users at each water-using end can turn on the waterfall washing mode so that people at all water-using ends can share hot water with a large flow rate.

[0007] Exemplarily, the controller controls the booster pump and the gas regulating valve according to the flow rate change range to control the gas water heater to turn on the waterfall washing mode, including performing the following operations: when it is determined that the first preset condition is met according to the flow rate change range, control the gas regulating valve and the booster pump so that the outlet water temperature of the gas water heater is the desired temperature of the water flow and the output water flow rate is greater than the rated water flow rate to turn on the waterfall washing mode; wherein, the first preset condition includes: there are the first preset number of flow rate drops within the first preset time, and there is a flow rate rise after each flow rate drop, wherein, when each flow rate drops, the flow rate drop amplitude is greater than or equal to the first amplitude threshold, and when each flow rate rises, the flow rate rise amplitude is greater than or equal to the second amplitude threshold.

[0008] In the above technical solution, by having the first preset number of flow rate drops within the first preset time and having a flow rate rise after each flow rate drop to turn on the waterfall washing mode, it helps users to accurately control the gas water heater to start the waterfall washing mode by conveniently operating the water-using end, effectively preventing the mis-triggering of the waterfall washing mode. In addition, when the user does not want to turn on the waterfall washing mode but accidentally operates some steps, the start of the waterfall washing mode can be prevented only by waiting.

[0009] Exemplarily, the first preset condition further includes: the time interval between the occurrence time of the first flow rate rise and the occurrence time of the last flow rate drop is less than the second preset time, wherein the second preset time is less than the first preset time.

[0010] In the above technical solution, by timing the second preset time, the occurrence of mis-triggering the waterfall washing mode can be effectively avoided, improving the user experience.

[0011] Exemplarily, the first preset condition further includes: before the first moment, the flow rate signal of the flow meter indicates that the water flow flows at a flow rate within a preset flow rate range for at least the third preset time, wherein the first moment is the starting moment of the first preset time.

[0012] In the above technical solution, after determining that the water flow rate is stable based on the flow signal, it is then determined whether to turn on the waterfall washing mode. This can effectively avoid the situation where the waterfall washing mode is accidentally turned on due to the user's daily water use, and thus avoid unnecessary calculations, which is easy to implement and not prone to errors.

[0013] Exemplarily, the gas water heater further includes a first temperature sensor disposed at the water inlet of the water circuit and a second temperature sensor disposed at the water outlet of the water circuit. The first temperature sensor is used to detect the water flow temperature at the water inlet of the water circuit, and the second temperature sensor is used to detect the water flow temperature at the water outlet of the water circuit; the controller controls the booster pump and the gas regulating valve according to the flow rate change amplitude to control the gas water heater to turn on the waterfall washing mode, including performing the following operations: when it is determined that the first preset condition is satisfied according to the flow rate change amplitude, controlling the booster pump to boost the water flow in the water circuit at a first lift, and the first lift is greater than the rated lift of the booster pump; calculating the heat required to heat the boosted water flow from the current water flow temperature at the water inlet to the desired water flow temperature; determining whether the rated heat load of the gas water heater can provide the required heat; in the case where the rated heat load is insufficient to provide the required heat, controlling the gas regulating valve to work under a first working condition so that the water outlet temperature reaches the desired temperature. When the gas regulating valve 210 works under the first working condition, the heat load of the gas water heater is greater than its rated heat load.

[0014] In the above technical solution, the controller can automatically and accurately determine whether the water outlet temperature can reach the user's desired temperature under the current water flow rate. Thus, when the gas water heater works in the waterfall washing mode, by controlling the gas regulating valve to adjust the real-time heat power of the burner, the heat load of the water heater is increased. This can not only provide a good experience for the user to ensure the constant temperature hot water output of the water heater when taking a large amount of hot water, but also has a simple control logic.

[0015] Exemplarily, the controller is further configured to, when the gas regulating valve works under the first working condition, perform a fifth timing operation on the duration of the gas regulating valve working under the first working condition; when the time counted by the fifth timing operation reaches a third preset duration, control the gas water heater to exit the waterfall washing mode.

[0016] In the above technical solution, by setting a third preset duration that allows the gas regulating valve to work under the first working condition to control the gas water heater to automatically exit the waterfall washing mode, it can be ensured that the gas regulating valve will not be damaged or the damage is within an acceptable range. Thus, the service life of the gas water heater is extended, and a significant performance decline is prevented.

[0017] Exemplarily, the water path includes a water inlet and a water outlet. The water inlet and the water outlet of the water path are respectively used to connect with the water outlet and the water inlet of the peripheral circulation pipeline of the gas water heater. The controller is further configured to control the gas water heater to exit the waterfall washing mode, and for the case where the flow signal indicates that the water flow rate is 0 L / min after exiting the waterfall washing mode, control the booster pump to continue running for a fourth preset time and then stop working.

[0018] In the above technical solution, after exiting the waterfall washing mode, controlling the booster pump to continue running for a fourth preset time and then stop working can quickly reduce the water temperature in the water path of the gas water heater, prevent the outlet water temperature from being too high in a short time, affect the user experience or even scald the user.

[0019] Exemplarily, the gas water heater further includes a first temperature sensor disposed at the water inlet of the water path for detecting the water flow temperature at the water inlet of the water path. The controller is further configured to: perform a fourth timing operation on the duration of the gas water heater operating in the waterfall washing mode when the gas water heater is operating in the waterfall washing mode; store the detected water flow temperature at the water inlet when the counted time in the fourth timing operation reaches a first preset duration; calculate the temperature sum of the stored water flow temperature at the water inlet and a first preset temperature; determine whether the current water flow temperature at the water inlet is greater than or equal to the temperature sum; and control the gas water heater to exit the waterfall washing mode when the current water flow temperature at the water inlet is greater than or equal to the temperature sum.

[0020] In the above technical solution, by detecting the change in the water flow temperature at the water inlet to determine whether the user has finished using water, the waterfall washing mode can be automatically exited in a timely manner. This effectively avoids waste of resources and is more user-friendly.

[0021] Exemplarily, the gas water heater further includes a first temperature sensor disposed at the water inlet of the water path for detecting the water flow temperature at the water inlet of the water path. The controller is further configured to: calculate the temperature difference between the desired temperature of the water flow and a second preset temperature when the gas water heater is operating in the waterfall washing mode; determine whether the current water flow temperature at the water inlet is greater than or equal to the temperature difference; and control the gas water heater to exit the waterfall washing mode when the current water flow temperature at the water inlet is greater than or equal to the temperature difference.

[0022] In the above technical solution, by comparing the water flow temperature at the water inlet with the desired temperature, it is also possible to determine whether the user has finished taking a bath or no longer needs a large flow of hot water, and the waterfall washing mode can be automatically exited in a timely manner, effectively avoiding waste of resources and being more user-friendly.

[0023] Exemplarily, the controller is further configured to, when the gas water heater is operating in the waterfall washing mode, control the gas water heater to exit the waterfall washing mode when the flow rate drop amplitude is greater than or equal to a third amplitude threshold.

[0024] In the above technical solution, when the gas water heater operates in the waterfall washing mode, it exits the waterfall washing mode according to the flow rate decrease. Such a control logic is simple and not prone to errors.

[0025] According to another aspect of the present invention, there is provided a control method for a gas water heater. The gas water heater includes: a water circuit, a flow meter provided on the water circuit, a burner for heating the water flow in the water circuit, and a gas pipeline for supplying gas to the burner. A gas regulating valve is provided on the gas pipeline. The control method includes: determining the flow rate change range of the water flow according to the flow rate signal from the flow meter; controlling the booster pump and the gas regulating valve according to the flow rate change range to control the gas water heater to start the waterfall washing mode, wherein the booster pump is used to connect to the water circuit, and when the gas water heater operates in the waterfall washing mode, the booster pump makes the output water flow rate of the gas water heater greater than the rated water flow rate.

[0026] In the summary of the invention, a series of simplified concepts are introduced, which will be further described in detail in the detailed implementation section. The summary of the invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0027] The following will, with reference to the accompanying drawings, detail the advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The following drawings of the present invention are used as part of the present invention to understand the present invention. The embodiments of the present invention shown in the drawings and their descriptions are used to explain the principles of the present invention. In the drawings,

[0029] Figure 1 is a schematic block diagram of a gas water heater according to an exemplary embodiment of the present invention;

[0030] Figure 2a is a schematic diagram showing the change of the water flow rate in the water circuit of a gas water heater over time according to an exemplary embodiment of the present invention;

[0031] Figure 2b is a schematic diagram showing the change of the water flow rate in the water circuit of a gas water heater over time according to another exemplary embodiment of the present invention;

[0032] Figure 3 is a flowchart of a control method for a gas water heater according to an exemplary embodiment of the present invention; and

[0033] Figure 4 is a flowchart of a control method for a gas water heater according to another exemplary embodiment of the present invention. Among them, the above drawings include the following reference numerals:

[0034] 100, Waterway; 101, Inlet of the waterway; 102, Outlet of the waterway; 110, Booster pump; 120, Flowmeter; 200, Gas pipeline; 210, Gas regulating valve; 220, Burner; 300, Controller. Detailed implementation

[0035] In the following description, a large number of details are provided to enable a thorough understanding of the present invention. However, those skilled in the art can understand that the following description only exemplarily shows the preferred embodiments of the present invention, and the present invention can be implemented without one or more such details. In addition, to avoid confusion with the present invention, some well-known technical features in the art are not described in detail.

[0036] To thoroughly understand the embodiments of the present invention, detailed structures will be presented in the following description. Obviously, the implementation of the embodiments of the present invention is not limited to the specific details familiar to those skilled in the art. The preferred embodiments of the present invention are described in detail below. However, in addition to these detailed descriptions, the present invention can also have other embodiments.

[0037] An embodiment of the present invention provides a gas water heater. Figure 1 A schematic block diagram of a gas water heater according to an exemplary embodiment of the present invention is shown.

[0038] The gas water heater may include a waterway 100. The inlet 101 of the waterway is used to connect to the municipal waterway. The water flow can be heated within the waterway 100. The outlet 102 of the waterway is used to connect to the peripheral pipelines in the user's home, such as the water using pipelines. When the user opens the water using end, hot water can flow out from the outlet of the hot water for the user to use. A flowmeter 120 may also be provided on the waterway 100. The flowmeter 120 can detect the water flow rate within the waterway 100 and generate a flow signal. The flowmeter 120 may include one or more of common flowmeters such as differential pressure flowmeters, volumetric flowmeters, and ultrasonic flowmeters.

[0039] The gas water heater may further include a burner 220 for heating the water flow in the waterway 100 and a gas pipeline 200 for supplying gas to the burner 220. A gas regulating valve 210 is provided on the gas pipeline 200. In other words, the gas regulating valve 210 and the burner 220 are connected in series along the gas flow direction on the gas pipeline 200 in sequence, and the gas regulating valve 210 is upstream of the burner 220. The gas pipeline 200 can be connected to the gas inlet of the gas water heater. The burner 220 can convert the chemical energy of the gas into heat energy, thereby heating the cold water in the waterway 100. The gas regulating valve 210 may include a proportional valve. The proportional valve can adjust the delivery flow rates of the gas and air, thereby regulating the amount of gas burned per unit time in the burner 220, and further regulating the thermal power output by the burner 220.

[0040] The gas water heater may further include a controller 300, which is connected to the flow meter 120, the booster pump 110, and the gas regulating valve 210. The controller 300 can be used to determine the flow rate change range of the water flow according to the flow signal from the flow meter 120, and control the booster pump 110 and the gas regulating valve 210 according to the flow rate change range to control the gas water heater to turn on the waterfall washing mode. It can be understood that the flow rate change range may include the flow rate increase range in the case of flow rate increase and the flow rate decrease range in the case of flow rate decrease. The controller 300 can be implemented using various chips, such as a Field-Programmable Gate Array (FPGA), a Micro-Processor Unit (MPU), a Programmable Logic Controller 300 (PLC), a Micro-Controller Unit (MCU), etc.

[0041] The booster pump 110 is used to connect to the water circuit 100 to boost the water flow in the water circuit 100. As Figure 1 shown, the booster pump 110 can be a part of the gas water heater and is arranged inside the housing of the gas water heater. The booster pump 110 can also be arranged on the peripheral pipeline of the gas water heater. It can be understood that as long as the booster pump 110 is connected to the water circuit 100 and can boost the water flow in the water circuit 100. The booster pump 110 can be various existing or future-developed booster water pumps, such as a single-pipeline booster pump 110, a DC booster pump 110, or a self-priming whole-house booster pump 110, etc. When the gas water heater operates in the waterfall washing mode, the booster pump 110 makes the output water flow rate of the gas water heater greater than the rated water flow rate.

[0042] When the controller 300 determines that the flow rate change range of the water flow has specific characteristics, it can control the booster pump 110 to operate and control the gas regulating valve 210 to increase the thermal power output by the burner 220. Thus, the output water flow rate of the gas water heater is greater than the rated water flow rate, and its waterfall washing mode is turned on. Specifically, for example, the gas water heater can be set with at least two working modes: normal and waterfall washing. When the gas water heater operates in the normal mode, its output water flow rate is less than or equal to the rated water flow rate. When the gas water heater operates in the waterfall washing mode, its output water flow rate is greater than the rated water flow rate, and it can quickly provide a relatively large amount of hot water for users to use. When, for example, users need to use hot water at multiple points simultaneously or use a relatively large amount of hot water at a single point, the users can select the waterfall washing mode.

[0043] Exemplarily, the specific features for controlling the flow rate change range of the water flow in the waterfall washing mode of the gas water heater can be set in advance. Specifically, for example, the flow rate change range of the water flow changes according to the following rule within the first preset time: First, the flow rate decreases and the flow rate decrease amplitude ≥ 1.5 liters per minute (L / min); after the flow rate decreases, the flow rate increases and the flow rate increase amplitude ≥ 1.5 L / min; after the flow rate increases, the flow rate decreases again, and the flow rate decrease amplitude ≥ 1.5 L / min; after the flow rate decreases again, the flow rate increases again and the flow rate increase amplitude ≥ 1.5 L / min.

[0044] When a water-using end of the gas water heater is opened or opened wider, the flow rate detected by the flow meter 120 provided on the water circuit 100 increases. When another water-using end is opened or opened wider, the curve of the flow rate further rises. When any water-using end is closed or closed smaller, vice versa. Specifically, for example, when multiple water-using ends draw water simultaneously, the flow rate detected by the flow meter 120 provided on the water circuit 100 is 5 L / min. At this time, if one water-using end stops drawing water, the water flow rate may drop to 3 L / min, that is, the flow rate decrease amplitude is 2 L / min at this time. Subsequently, when this water-using end is opened, the water flow rate may return to 5 L / min. Then, this water-using end is successively closed and opened. During the above entire process, the controller 300 can determine that the flow rate change ranges of the water flow are successively a flow rate decrease of 2 L / min, a flow rate increase of 2 L / min, a flow rate decrease again of 2 L / min, and a flow rate increase again of 2 L / min according to the flow rate signal from the flow meter 120. If it can be determined that the flow rate change range has the above features, the waterfall washing mode can be turned on.

[0045] When the controller 300 determines that the flow signal has specific characteristics, the waterfall washing mode of the gas water heater can be turned on. The controller 300 can control the booster pump 110 to increase the pressure of the water flow in the water circuit 100 at a first head greater than its rated head. Specifically, for example, the controller 300 can provide an input current exceeding its rated current to the booster pump 110 to control the output power of the booster pump 110, thereby controlling the booster pump 110 to increase the pressure of the water flow in the water circuit 100 at the first head. In one example, the rated water flow of the gas water heater is 12 L / min, and in its waterfall washing mode, under the action of the booster pump 110 operating at the first head, its output water flow can reach 16 L / min. Preferably, in the waterfall washing mode, the water output flow is 20%-100% greater than the water flow in the normal mode. It can be understood that as the output water flow of the gas water heater increases, in order to make the outlet water reach the desired temperature, the heat load of the gas water heater also increases accordingly. The desired temperature can be a temperature preset by the user using the input device, such as 60 degrees. To increase the heat load of the gas water heater, the controller 300 can also control the gas regulating valve 210 to operate under the first working condition. Specifically, for example, the controller 300 can provide a larger input current to the gas regulating valve 210 to increase the opening degree of the gas regulating valve 210. As a result, the gas flow in the gas pipeline increases, and the thermal power of the burner 220 of the gas water heater increases. By using the controller 300 to control the booster pump 110 and the gas regulating valve 210 according to the flow signal, the gas water heater can enter the waterfall washing mode as desired.

[0046] In the above technical solution, by detecting the flow signal in the water circuit 100 of the gas water heater and determining the flow change amplitude according to the flow signal, and then controlling the booster pump 110 and the gas regulating valve 210 according to the flow change amplitude, the waterfall washing mode of the gas water heater can be remotely turned on. This can conveniently provide hot water with a water flow greater than the rated water flow for the user, significantly improving the user's bathing experience. Compared with controlling the gas water heater through other remote control devices or intelligent devices, the above operation is more convenient, safer, and has higher reliability. In addition, regardless of how many water use terminals are connected to the water circuit 100 of the gas water heater, during the water intake process, the flow change amplitude of the water flow can reach specific characteristics by opening and closing any water use terminal, and the waterfall washing mode can be turned on. This solution is applicable to occasions where multiple people use water. Users at each water use terminal can turn on the waterfall washing mode, enabling people at all water use terminals to share hot water with a large flow.

[0047] Exemplarily, the controller 300 controls the booster pump 110 and the gas regulating valve 210 according to the flow rate change amplitude to control the gas water heater to turn on the waterfall washing mode, including performing the following operations. When it is determined that the first preset condition is met according to the flow rate change amplitude, the gas regulating valve 210 and the booster pump 110 are controlled to make the outlet water temperature of the gas water heater the desired temperature and the output water flow rate greater than the rated water flow rate, so as to turn on the waterfall washing mode. The first preset condition includes: there are a first preset number of flow rate drops within a first preset time, and there is a flow rate rise after each flow rate drop, where the flow rate drop amplitude is greater than or equal to a first amplitude threshold each time the flow rate drops, and the flow rate rise amplitude is greater than or equal to a second amplitude threshold each time the flow rate rises.

[0048] The first preset time and the first preset number can be adjusted as needed. The first preset time and the first preset number can be set in the controller 300 during production, or can be set by the user himself. The first preset time can be 60 - 250 seconds. It can be understood that if the first preset time is too long, the user is very likely to accidentally trigger the waterfall washing mode during normal use; if the first preset time is too short, the user may not have enough time to complete the specific operation to turn on the waterfall washing mode. The first preset number can be 2 - 5 times. If the first preset number is set too small, the waterfall washing mode may be accidentally triggered. If the first preset number is set too large, it may make it too difficult to turn on the waterfall washing mode and affect the user experience.

[0049] The first amplitude threshold and the second amplitude threshold can be the same or different. The first amplitude threshold and the second amplitude threshold can be set in the controller 300 of the gas water heater when it leaves the factory. Preferably, the gas water heater can be provided with an input device for the user to set the first amplitude threshold and the second amplitude threshold according to the water usage situation by himself. If the first amplitude threshold and the second amplitude threshold are set too small, the waterfall washing mode is very likely to be accidentally triggered due to normal fluctuations in the water circuit 100, and if they are set too large, it will be difficult to turn on the waterfall washing mode and the operation is complicated. Therefore, only by reasonably setting the first amplitude threshold and the second amplitude threshold can the waterfall washing mode be turned on more easily and is not easily affected by fluctuations in the water circuit 100, providing a good user experience. According to an embodiment of the present invention, the above first amplitude threshold and second amplitude threshold are 1 to 2 L / min.

[0050] During the operation of the gas water heater, the controller 300 can continuously determine whether the current first preset condition is satisfied. When the user is using the hot water of the gas water heater at a water usage end, the controller 300 can first determine whether the flow signal generated by the flow meter 120 indicates a decrease in the water flow in the water path 100, and the decrease amplitude is greater than or equal to the first amplitude threshold. It can be understood that the decrease in the water flow in the water path 100 may be triggered by the user closing a water usage end. After determining the first water flow decrease and the decrease amplitude is greater than or equal to the first amplitude threshold based on the flow signal, the waterfall washing judgment timing operation can be started. This waterfall washing judgment timing operation can last for at most the first preset time. After the controller 300 determines the above-mentioned first water flow decrease, it can continue to determine whether the flow signal of the water flow indicates an increase in the water flow. The increase in the water flow may be triggered by the user opening a water usage end. After the water flow increases, when the user closes the water usage end again, the flow signal can indicate the second water flow decrease. After that, if the flow signal indicates that the water flow increases for the second time after the second water flow decrease, and the decrease amplitude of each water flow decrease is greater than or equal to the first amplitude threshold, and the increase amplitude of each water flow increase is greater than or equal to the second amplitude threshold, the waterfall washing mode is turned on and the waterfall washing judgment timing operation is stopped. In other words, during the above process, the user may sequentially perform operations of closing the faucet, opening the faucet, closing the faucet again, and opening the faucet again, thereby turning on the waterfall washing mode. During the execution of the waterfall washing judgment timing operation, if the waterfall washing judgment timing operation has lasted for the first preset time and the first preset condition has not been satisfied, the above-mentioned judgment operation on the flow change amplitude may not be continued, but instead, it is determined again whether a new water flow decrease has occurred.

[0051] In addition, during the above-mentioned waterfall washing judgment timing operation, except for the water usage end operated by the user, the continuous water usage of other water usage ends has no impact on the above-mentioned judgment of the flow change amplitude. It can be understood that the time required for the user to sequentially perform operations of closing the faucet, opening the faucet, closing the faucet again, and opening the faucet again is relatively short. During this process, the possibility of water flow changes in other water usage ends is small. Therefore, other water usage ends hardly interfere with the process of turning on the waterfall washing mode in the embodiments of the present invention.

[0052] Figure 2a and Figure 2b respectively show the schematic diagrams of the change of the water flow in the water path 100 over time according to an embodiment of the present invention. As Figure 2a and Figure 2b shown, the change of the water flow over time can be represented as a curve. In Figure 2a and Figure 2bIn the illustrated embodiment, the first preset time is 125 seconds and the first preset number of times is 2 times. The first threshold amplitude is equal to the second threshold amplitude, both equal to 1.5 L / min.

[0053] In Figure 2a In the illustrated embodiment, at time T = 5.5 seconds, the water flow rate is 6 L / min. The first flow rate drop occurs at 10 seconds, and the drop amplitude is 1 L / min. At this time, the drop amplitude of the flow rate is less than the first amplitude threshold of 1.5 L / min, so the condition is not met, and the controller 300 continues to wait for the next flow rate drop. At 12.5 seconds, the water flow rate continues to drop, and the drop amplitude is 2 L / min. Since the drop amplitude of the flow rate is greater than the first amplitude threshold, the controller 300 determines that the condition is met, starts the waterfall wash judgment timing operation, and starts waiting for the next change in the water flow rate. At 14.5 seconds, the flow rate rises, and the rise amplitude is 2 L / min. Since the rise amplitude of the flow rate is greater than the second amplitude threshold, the controller 300 determines that the condition is met and continues to wait for the next change in the water flow rate. When reaching 137.5 seconds (not shown), the waterfall wash judgment timing operation has been timed for 125 seconds, but according to the flow rate change amplitude, the first preset condition is never met, so the waterfall wash mode is not turned on. At this time, the controller 300 can restart the detection of whether a flow rate drop has occurred and discard the previously detected results. When the flow rate drops and the drop amplitude is greater than the first amplitude threshold, the waterfall wash judgment timing operation is restarted...

[0054] In examples such as the above Figure 2a In the illustrated example, when the time counted by the waterfall wash judgment timing operation reaches 125 seconds but the first preset condition is not met according to the flow rate signal, the waterfall wash mode is not turned on. For example, the user may simply expect to close the water-using end after the bath, then the controller 300 determines only that a flow rate drop has occurred within 125 seconds according to the flow rate signal. Another example is that the user may close the water-using end and then open it again to restart the bath. Then, after the controller 300 determines the first flow rate drop of the water flow within 125 seconds according to the flow rate signal, it also determines the first flow rate rise, and after the first flow rate rise, the water flow rate may remain unchanged for a long time. In these examples, when the time counted by the waterfall wash judgment timing operation reaches 125 seconds, no operation to change the working condition of the booster pump 110 is performed, and the gas control valve 210 is controlled to operate in the normal mode.

[0055] As Figure 2bAs shown, at 22 seconds, the water flow rate decreases, and the decrease amplitude is 1.5 L / min. The decrease amplitude is equal to the first amplitude threshold, and the controller 300 determines that the condition is satisfied. It waits for the next change in the water flow rate and starts the waterfall washing judgment timing operation. At 23 seconds, the water flow rate increases, and the increase amplitude is 3 L / min. The increase amplitude is greater than the second amplitude threshold, and the controller 300 determines that the condition is satisfied and starts waiting for the next change in the water flow rate. At 25 seconds, the water flow rate decreases, and the decrease amplitude is 3 L / min. The decrease amplitude is greater than the first amplitude threshold, and the controller 300 determines that the condition is satisfied and starts waiting for the next change in the water flow rate. Between 26.5 seconds and 27 seconds, the water flow rate increases, and the increase amplitude is 1.5 L / min. The increase amplitude is equal to the second amplitude threshold, and the controller 300 determines that the condition is satisfied. And the time counted by the waterfall washing judgment timing operation is 27 - 22 = 5 seconds at this time, which is less than the first preset time, so the waterfall washing mode is turned on.

[0056] In the case where the user only uses one water-using end, as long as the user uses water normally, interrupting the water flow means that the flow rate decreases, and the decrease amplitude is greater than or equal to the first amplitude threshold. Taking the first amplitude threshold of 1.5 L / min as an example, only fine adjustment can make the change amplitude of the flow rate less than 1.5 L / min, and the change amplitude of the flow rate generated by normal opening and closing of the water-using end will be greater than this value. For the case where multiple water-using ends use water simultaneously, although the water flow rate of each water-using end may become smaller due to water grabbing by other water-using ends, the change amplitude of the flow rate generated by normal opening and closing of the water-using end will still be greater than or equal to 1.5 L / min. For the sake of concise description, the following flow rate decrease means that the decrease amplitude is greater than or equal to the first amplitude threshold, and the flow rate increase means that the increase amplitude is greater than or equal to the second amplitude threshold.

[0057] In the above technical solution, by having the flow rate decrease occur a first preset number of times within the first preset time and a flow rate increase occur once after each flow rate decrease to turn on the waterfall washing mode, it helps the user to accurately control the gas water heater to start the waterfall washing mode by conveniently operating the water-using end, effectively preventing the mis-triggering of the waterfall washing mode. In addition, when the user does not want to turn on the waterfall washing mode but misoperates some steps, the waterfall washing mode can be prevented from being turned on only by waiting. By reasonably setting the first amplitude threshold and the second amplitude threshold, the waterfall washing mode can be more easily turned on and is not easily affected by the fluctuation of the water circuit 100, greatly improving the reliability of control and providing a good user experience.

[0058] Exemplarily, the first preset condition may further include: the time interval between the occurrence time of the first flow rate increase and the occurrence time of the last flow rate decrease is less than the second preset time, where the second preset time is less than the first preset time.

[0059] During the water usage process, it is rare to frequently open and close the water-using end within a short period of time. For most users, during normal water usage, they will not frequently and significantly adjust the water flow rate multiple times within a short period. For example, by turning the faucet on and off. Since the gas water heater activates the waterfall washing mode based on a specific change range of the flow rate, a second preset time can be set. In the example where the first preset time is 125 seconds, the second preset time can be 5 seconds. Exemplarily but not restrictively, the second preset time can be from 3 to 30 seconds. If the second preset time is too long, the user is very likely to accidentally trigger the waterfall washing mode during normal use. If the second preset time is too short, the user may not have enough time to complete a specific operation to activate the waterfall washing mode. As described above, to activate the waterfall washing mode, within the first preset time, there must be a first preset number of flow rate drops, and a flow rate increase occurs after each flow rate drop. Exemplarily, the controller 300 can perform the following operations to control the gas regulating valve 210 and the booster pump 110 to activate the waterfall washing mode. First, starting from the first flow rate drop, a second timing operation is initiated. The duration of the second timing operation is at most the difference between the first preset time and the second preset time. In the above embodiment, 125 - 5 = 120 seconds. If within 120 seconds, no flow rate increase is detected, the second timing operation is stopped, and after waiting for the next flow rate drop, the second timing operation is restarted. Before the second timing operation, only flow rate drops are detected, and no action is taken for flow rate increases. If during the second timing operation, that is, within 120 seconds, a flow rate increase is detected, a third timing operation for the second preset time (i.e., the aforementioned 5 seconds) is started. If within 5 seconds, (the first preset number - 1) flow rate drops occur, and a flow rate increase occurs after each flow rate drop, the waterfall washing mode is activated. In another example, if within 5 seconds, (the first preset number - 1) flow rate drops do not occur or no flow rate increase occurs after any flow rate drop, the waterfall washing mode is not activated, and the third timing operation is restarted. If the waterfall washing mode cannot be successfully activated within 125 seconds, after the next flow rate drop, the 120-second timing is restarted.

[0060] In the above technical solution, through the timing of the second preset time, the occurrence of accidentally triggering the waterfall washing mode can be effectively avoided, improving the user experience.

[0061] Exemplarily, the first preset condition may further include: before the first moment, the flow signal of the flowmeter 120 indicates that the water flow flows at a flow rate within a preset flow rate range for at least a third preset time, where the first moment is the starting moment of the first preset time. Exemplarily, the third preset time may be any value from 3 to 15 seconds. In one example, the third preset time is 5 seconds. Usually, after the user starts using water, for example, after opening the water-using end, there is a need to activate the waterfall washing mode. In this example, when the controller 300 determines that the water flow rate belongs to the preset flow rate range according to the flow signal, the first timing operation is started. If the time counted by the first timing operation reaches 5 seconds and the water flow rate is always within the preset flow rate range, the first timing operation is stopped and it is started to determine whether the flow signal indicates that a first preset number of flow rate drops occur within the first preset time, and a flow rate rise occurs after each flow rate drop.

[0062] It can be understood that within the 5 seconds counted by the first timing operation, the water flow rate can fluctuate as long as it is always within the preset flow rate range. Thus, at any moment after the counted time reaches 5 seconds, the waterfall washing mode can be activated according to the flow signal of the water flow, that is, any such moment can be used as the starting moment for determining whether the water flow has a first preset number of flow rate drops and a flow rate rise occurs after each flow rate drop, that is, the first moment. If the water flow rate exceeds the preset flow rate range before the counted time reaches 5 seconds, the first timing operation is stopped and waiting for the water flow rate to return to the preset flow rate range again to start the first timing operation again. It can be understood that the hot water output from the water outlet of the gas water heater may supply multiple water-using ends. During daily water use, it may occur that the faucets of different water-using ends are switched on and off multiple times in a short period, thereby changing the water flow rate of the gas water heater multiple times. These situations may cause the waterfall washing mode to be triggered erroneously, causing inconvenience to the user. Exemplarily but not limitatively, a flow rate lower limit value, such as 2.7 L / min, may be set in the above preset flow rate range. When the value of the water flow rate is always greater than or equal to 2.7 L / min within 5 seconds, it can be considered that the current water flow rate in the water path 100 is stable. After the water flow rate is stable, the judgment operation of determining whether the flow signal has specific characteristics is performed to further determine whether to activate the waterfall washing mode.

[0063] In the above technical solution, after determining that the water flow rate is stable based on the flow signal, it is further determined whether to activate the waterfall washing mode. This can effectively avoid the situation that the waterfall washing mode is erroneously activated due to the user's daily water use, and thus avoid unnecessary calculations, is easy to implement and not prone to errors.

[0064] Exemplarily, the gas water heater may further include a first temperature sensor disposed at the water inlet of the water path 100 and a second temperature sensor disposed at the water outlet of the water path 100. The first temperature sensor may be configured to detect the water flow temperature at the water inlet of the water path 100, and the second temperature sensor may be configured to detect the water flow temperature at the water outlet of the water path 100. In some cases, the water flow temperature at the water inlet of the water path 100 may vary with seasons. In this case, the setting of the first temperature sensor enables the controller 300 to more precisely control the booster pump 110 and the gas regulating valve 210 based on the temperature of the incoming water, ensuring that the water flow temperature at the water outlet reaches the temperature desired by the user.

[0065] The controller 300 controls the booster pump 110 and the gas regulating valve 210 according to the flow rate change amplitude to control the gas water heater to turn on the waterfall washing mode, which may include performing the following operations.

[0066] First, when it is determined that the first preset condition is satisfied according to the flow rate change amplitude, the booster pump 110 is controlled to boost the water flow in the water path 100 at a first head. In the normal operating mode of the gas water heater, the booster pump 110 may provide pressure for the water in the water path 100 at a power less than or equal to the rated power. In the waterfall washing mode, the water consumption increases significantly, and the gas water heater needs to provide hot water exceeding its rated flow rate. At this time, the booster pump 110 may operate at a power greater than the rated power. At this time, the head of the booster pump 110 may be the first head. The first head is greater than the rated head of the booster pump 110.

[0067] The booster pump 110 is a device that pressurizes the water flow in the water path 100 by driving a pumping device with an electric motor. The booster pump 110 may adopt a DC motor, which has good anti-overload performance and will not be damaged even if it operates for a certain period of time under overload conditions. The booster pump 110 may have a certain power margin when leaving the factory, that is, the rated power is less than the limit power of the booster pump 110. Therefore, the controller 300 may apply a working voltage higher than the rated voltage to the booster pump 110 in the waterfall washing mode, so that the booster pump 110 operates for a short time under the condition of higher than the rated power and not higher than the limit power, greatly increasing the hot water flow rate of the water heater and meeting the user's needs.

[0068] Exemplarily, before the controller 300 controls the booster pump 110 to boost the water flow in the water circuit 100 at a first lift, the controller 300 may further determine whether the flow rate of the water flow is within a first flow rate range. Only when the flow rate of the water flow is within the first flow rate range, the booster pump 110 is controlled to boost the water flow in the water circuit 100 at the first lift. An upper limit value may be set for the first flow rate range, and the upper limit value may be less than or equal to the rated flow rate of the gas water heater. Exemplarily, for a gas water heater with a rated flow rate of 13 L / min, the upper limit value may be 10 L / min. If the current flow rate has exceeded the upper limit value, the booster pump 110 does not start boosting. If the current flow rate is less than the upper limit value and it is determined that the conditions for starting the waterfall washing mode are met, the water flow in the water circuit 100 is additionally boosted by the booster pump 110.

[0069] In the above technical solution, when the flow rate of the water flow is within the first flow rate range, the booster pump 110 is controlled to start and boost the water flow in the water supply pipeline at the first lift. This can ensure that the gas water heater can output hot water at a desired temperature for the user and improve the user experience.

[0070] The controller 300 controls the booster pump 110 and the gas regulating valve 210 according to the flow rate change amplitude to control the gas water heater to start the waterfall washing mode, and may further include performing the following operations: calculating the heat required to heat the boosted water flow from the current water temperature at the water inlet to the desired water temperature; determining whether the rated heat load of the gas water heater can provide the required heat; and when the rated heat load is insufficient to provide the required heat, controlling the gas regulating valve 210 to operate under a first working condition so that the water temperature at the water outlet reaches the desired temperature. When the gas regulating valve 210 operates under the first working condition, the heat load of the gas water heater is greater than its rated heat load.

[0071] When the water heater outputs hot water at the rated flow rate, the rated heat load can provide hot water at the desired temperature. After the water heater starts the waterfall washing mode, since the water flow rate is greater than the rated flow rate, the water heater may not be able to provide water with a relatively high temperature. At this time, the controller 300 may calculate the heat required to heat the water flow to the desired temperature according to the water temperature at the water inlet and the desired temperature.

[0072] For example, the controller 300 may determine the heat Q required to bring the water flow at the current flow rate to the desired temperature according to the following formula:

[0073] Q = f * (T2 - T1) * n,

[0074] Among them, T2 is the desired temperature, T1 is the water flow temperature at the water inlet, f is the current water flow rate, and n is the compensation coefficient of the gas water heater. Among them, T1 can be measured by the first temperature sensor at the water inlet, T2 can be set by the user, and f can be measured by the flow meter 120 provided on the water circuit 100. The compensation coefficient n is related to the performance of the water heater. It can be understood that due to differences in the design structures of different water heaters, even the same water heater may have different heating effects due to tolerances. Therefore, the compensation parameters of the water heater can be calculated through actual tests of the water heater. Through the above known quantities, the controller 300 can calculate the heat load Q required to bring the water flow at the current flow rate to the desired temperature.

[0075] Compare the calculated heat Q with the rated heat load Q0 of the water heater, and it can be determined whether the water heater can provide the required heat under the rated heat load Q0. When Q ≤ Q0, the controller 300 determines that the rated heat load can bring the water flow at the current flow rate to the desired temperature, and it can control the gas regulating valve 210 to operate under normal conditions. In this case, the water temperature output by the gas water heater is the desired temperature, and the water flow rate is greater than the rated water flow rate, which can meet the user's demand for waterfall washing. When Q > Q0, the controller 300 determines that the rated heat load cannot bring the water flow at the current flow rate to the desired temperature. If the controller 300 turns on the waterfall washing mode at the rated heat load at this time, the temperature of the hot water output will be lower than the desired temperature. This situation may be that the user's desired temperature is relatively high, or the water flow temperature at the water inlet is too low, or both. Turning on the waterfall washing mode at the rated heat load in this case will seriously affect the user experience. Therefore, in this case, the gas regulating valve 210 can be controlled to operate under the first condition to make the water temperature at the water outlet reach the desired temperature.

[0076] Exemplarily, the controller 300 controlling the gas regulating valve 210 to operate under the first condition may include performing the following operations: controlling the gas regulating valve 210 to operate at the first supply current, where the first supply current is greater than the rated supply current of the gas regulating valve 210. The gas regulating valve 210 can be made to operate under different conditions by adjusting its supply current. When operating at different supply currents, the opening degree of the gas regulating valve 210 is different, and thus, the gas flow rate passing through the gas regulating valve 210 is also different. Specifically, the controller 300 can control the gas regulating valve 210 to operate at the first supply current. This first supply current is greater than its rated supply current. As a result, the ventilation speed of the gas regulating valve 210 increases, and more gas enters the burner 220 of the water heater per unit time. The heat load of the water heater will be greater than its rated heat load.

[0077] Exemplarily, the controller 300 controlling the gas regulating valve 210 to operate under a first operating condition may include performing the following operations: controlling a pressurizing device to pressurize the gas passing through the gas regulating valve 210, wherein the pressurizing device is disposed within the gas regulating valve 210. Whether the pressurizing device starts or not significantly affects the gas throughput of the gas regulating valve 210. After starting, the pressurizing device can directly increase the gas throughput, whereby the gas supply speed of the burner 220 of the water heater is also correspondingly increased. When the gas regulating valve 210 is at a relatively large opening degree, for example, when its supply current is the rated supply current, starting the pressurizing device within the valve body of the gas regulating valve 210 can enable the gas regulating valve 210 to break through its gas throughput corresponding to the supply current, thereby making the heat load of the water heater greater than the rated heat load.

[0078] In the above technical solution, the controller 300 can automatically and accurately determine whether the outlet water temperature can reach the user's desired temperature at the current water flow rate. Thus, when the gas water heater operates in the waterfall washing mode, by controlling the gas regulating valve 210 to adjust the real-time heat power of the burner 220, the heat load of the water heater is increased. This can not only provide a good experience for the user to ensure the constant-temperature hot water output of the water heater when taking a large amount of hot water, but also has a simple control logic.

[0079] Exemplarily, the gas water heater further includes a blower for blowing air into the burner 220. The gas water heater uses gas as the energy for heating. During the combustion process of the gas, oxygen is required and carbon dioxide, water vapor, etc. will be generated. When the gas combustion is insufficient, there may also be generated toxic carbon monoxide. Setting a blower is a relatively conventional way to solve the above problems. The burner 220 may be provided with an air inlet, and the blower is disposed at the air inlet, and it can pump air into the burner 220 and at the same time blow away the combustion exhaust gas. Alternatively, the burner 220 may be provided with an air outlet, and the blower is disposed at the air outlet of the burner 220. The exhaust gas is taken away due to the negative pressure generated by the blower, and air is inhaled into the burner 220 through the air inlet. In this way, the flame in the burner 220 is not easily blown out by the blower. The controller 300 is further configured to control the rotational speed of the blower according to the opening degree of the gas regulating valve 210, wherein the rotational speed of the blower is positively correlated with the opening degree of the gas regulating valve 210. It can be understood that when the opening degree of the gas regulating valve 210 increases, the generated exhaust gas will also increase correspondingly. Especially when the gas water heater is in the waterfall washing mode, due to the increase in the output water flow rate, the opening degree of the gas regulating valve 210 will also adaptively increase. At this time, appropriately increasing the rotational speed of the blower according to the opening degree of the gas regulating valve 210 can discharge more exhaust gas, avoiding the accumulation of exhaust gas affecting the combustion efficiency or causing poisoning. Of course, when the opening degree of the gas regulating valve 210 decreases, the flame also decreases accordingly. At this time, reducing the rotational speed of the blower can avoid excessive convection within the burner 220 and cause the flame to go out.

[0080] On the one hand, the above technical solution ensures that the gas in the burner 220 of the gas water heater can burn smoothly, thus ensuring that the gas water heater can output hot water in a large flow rate, and further ensuring that the gas water heater continuously operates in the waterfall washing mode. On the other hand, it effectively discharges a large amount of waste gas generated by gas combustion.

[0081] Exemplarily, the controller 300 is further configured to perform a fifth timing operation on the duration of the gas control valve 210 operating in the first working condition when the gas control valve 210 operates in the first working condition. When the time counted by the fifth timing operation reaches the third preset duration, the gas water heater is controlled to exit the waterfall washing mode.

[0082] Taking the electromagnetic gas control valve 210 as an example, when the gas control valve 210 operates in the first working condition, the current output by the controller 300 to the gas control valve 210 is greater than the rated current of the gas control valve 210. At this time, the heat generated by the electromagnetic coil in the electromagnetic gas control valve 210 may increase. Exemplarily, a cooling device can be set to cool it, and its service life and performance will not be affected in a short time. However, if it operates in the first working condition for a long time, the life and performance of the gas control valve 210 may be damaged due to heat accumulation. Therefore, exemplarily, through multiple experiments, the third preset duration for the gas control valve 210 to operate in the first working condition without damaging the gas control valve 210 can be determined. When the time counted by the fifth timing operation reaches the third preset duration, the gas water heater is controlled to exit the waterfall washing mode, thereby avoiding damage to the gas control valve 210. Of course, the third preset duration can also be designed according to actual needs. For example, when the gas control valve 210 operates in the first working condition for the third preset duration, the damage situation is within an acceptable range. Since the heat generation situation of the gas control valve 210 is different at different currents, there may be a situation where the gas control valve 210 operates in the first working condition but the current is only slightly greater than the rated current, and a situation where the current of the gas control valve 210 is much larger than the rated current. The third preset duration can be set based on the maximum current that the gas control valve 210 may accept to prevent the gas control valve 210 from burning out.

[0083] In the above technical solution, by setting the third preset duration that allows the gas control valve 210 to operate in the first working condition to control the gas water heater to automatically exit the waterfall washing mode, it can ensure that the gas control valve 210 will not be damaged or the damage is within an acceptable range. Thus, the service life of the gas water heater is extended, and a significant decline in performance is prevented.

[0084] Exemplarily, the controller 300 is further configured to, when the gas water heater is operating in the waterfall washing mode, control the gas water heater to exit the waterfall washing mode when the flow rate drop amplitude is greater than or equal to the third amplitude threshold. When the user expects to use water in the waterfall washing mode, the user does not close or throttle the water-using end. Therefore, a sudden large drop in the flow rate can be used as a control signal to exit the waterfall washing mode. In other words, during the process of the gas water heater operating in the waterfall washing mode, if the user closes the water-using end or throttles the water-using end to a certain extent, it can be considered that the user expects to exit the waterfall washing mode. At this time, the flow rate drop amplitude of the water flow in the water path 100 can reflect this expectation of the user. Accordingly, the gas water heater can be controlled to exit the waterfall washing mode.

[0085] In the above technical solution, when the gas water heater is operating in the waterfall washing mode, it is controlled to exit the waterfall washing mode according to the flow rate drop amplitude. In this way, the control logic is simple and not prone to errors.

[0086] Exemplarily, the water path 100 includes a water inlet and a water outlet. The water inlet and the water outlet of the water path 100 are respectively used to connect with the water outlet and the water inlet of the peripheral circulation pipeline of the gas water heater. Thus, the peripheral circulation pipeline and the water path 100 of the gas water heater form a closed-loop water path 100, and the water flow can circulate within this closed-loop water path 100. The gas water heater arranged in this way can have the zero cold water function. The controller 300 is further configured to control the gas water heater to exit the waterfall washing mode, and for the case where the flow rate signal indicates that the water flow rate is 0 L / min after exiting the waterfall washing mode, control the booster pump 110 to continue running for a fourth preset time and then stop working.

[0087] In the waterfall washing mode, the heat load of the gas water heater is relatively high. When the user closes the water outlet of the gas water heater in the waterfall washing mode, the flow rate of the water flow in the water path 100 of the gas water heater drops to 0 L / min. At this time, the temperature of the water flow in the water path 100 of the water heater may continue to rise under the action of the residual temperature of the burner 220. If the user takes water, it may cause the outlet water temperature to be much higher than the expected temperature in a short time, affecting the user experience and even causing scalding. In this case, the booster pump 110 can be controlled to continue running, so that the water flow in the water path 100 circulates in the closed-loop pipeline for a fourth preset time, and the heat of the water flow is evenly absorbed. The fourth preset time can be adjusted according to the layout of the user's water path 100, or can be appropriately longer, so as to ensure that the water flow can cool down as much as possible in the water path 100.

[0088] In the above technical solution, after exiting the waterfall washing mode, controlling the booster pump 110 to continue running for a fourth preset time and then stop working can quickly reduce the water temperature in the water path 100 of the gas water heater, prevent the outlet water temperature from being too high in a short time, affect the user experience and even scald the user.

[0089] As described above, the gas water heater may further include a first temperature sensor disposed at the water inlet of the water circuit 100 for detecting the water flow temperature at the water inlet of the water circuit 100.

[0090] Exemplarily, the controller 300 is further configured to perform a fourth timing operation on the duration of the gas water heater operating in the waterfall washing mode when the gas water heater is operating in the waterfall washing mode. And when the counted time of the fourth timing operation is a first preset duration, store the detected water flow temperature T3 at the water inlet. It can be understood that in the example where the water circuit 100 of the above gas water heater forms a closed-loop water circuit 100 with an external circulation pipeline, when the waterfall washing mode is just started, the water flow at the water inlet is a mixed water flow of the water in the municipal pipeline and the hot water flowing back in the closed-loop pipeline, and its temperature is unstable. After the gas water heater operates in the waterfall washing mode for the first preset duration, the water flow at the water inlet basically comes from the municipal pipeline, and its temperature gradually stabilizes. The water flow temperature T3 after the first preset duration can be stored. The first preset duration can be any value from 10 to 30 seconds, for example, 20 seconds.

[0091] Thereafter, the sum of the stored water flow temperature T3 at the water inlet and the first preset temperature can be calculated at a preset frequency, and it is determined whether the current water flow temperature at the water inlet is greater than or equal to the sum of the temperatures. In the case where the current water flow temperature at the water inlet is greater than or equal to the sum of the temperatures, control the gas water heater to exit the waterfall washing mode. The first desired temperature can also be appropriately set according to the actual situation or experience. The first preset temperature can be any value from 5 to 15 degrees, for example, 10 degrees.

[0092] Since when the user continuously uses water when the gas water heater is operating in the waterfall washing mode, the water flow at the water inlet will basically come from the municipal pipeline, and its water temperature will generally remain at the water flow temperature T3. When the user finishes using water, the water flow at the water inlet of the water circuit 100 of the gas water heater no longer comes from the municipal pipeline, but will be the hot water flowing back in the closed-loop pipeline, and the water temperature at the water inlet may rise significantly. Thus, a significant rise in the water flow temperature at the water inlet can indicate that the user has closed the water use end, and at this time, the waterfall washing mode can be exited. Taking the foregoing first desired temperature of 10 degrees as an example, if the current water temperature at the water inlet is greater than or equal to T3 + 10, that is, the user has finished taking a bath, at this time, the waterfall washing mode can be exited.

[0093] In the above technical solution, it is determined whether the user has finished using water by detecting the change in the water flow temperature at the water inlet, and thus the waterfall washing mode is automatically exited in a timely manner. This effectively avoids waste of resources and is more user-friendly.

[0094] Exemplarily, the controller 300 can also be used to calculate the temperature difference between the desired temperature of the water flow and the second preset temperature when the gas water heater is operating in the waterfall washing mode, so as to determine whether the current water flow temperature at the water inlet is greater than or equal to the temperature difference. When the current water flow temperature at the water inlet is greater than or equal to the temperature difference, the gas water heater is controlled to exit the waterfall washing mode. The second desired temperature can also be appropriately set according to the actual situation or experience. The second preset temperature can be any value from 3 to 10 degrees, for example, 5 degrees.

[0095] When the user activates the waterfall washing mode, the water flow at the water inlet mainly comes from the municipal pipeline. Therefore, the water flow temperature at the water inlet is generally much lower than the desired temperature. When the hot water flow rate taken by the user is small or even when the user no longer takes hot water, the water flow at the water inlet will mainly or even entirely come from the closed-loop water path 100, and the water flow temperature at the water inlet will increase accordingly. When the water flow temperature at the water inlet is greater than the above temperature difference, it indicates that the water flow temperature at the water inlet is approaching the desired temperature, and the water heater does not need to activate the waterfall washing mode. Therefore, it can exit the waterfall washing mode to reduce energy consumption.

[0096] In the above technical solution, by comparing the water flow temperature at the water inlet with the desired temperature, it is also possible to determine whether the user has finished taking a bath or no longer needs a large flow of hot water, and can automatically exit the waterfall washing mode in a timely manner, effectively avoiding waste of resources and being more user-friendly.

[0097] According to another aspect of the present invention, a control method for a gas water heater is also provided. The gas water heater can include a water path 100, a flow meter 120 provided on the water path 100, a burner 220 for heating the water flow in the water path 100, and a gas pipeline 200 for supplying gas to the burner 220. A gas regulating valve 210 is provided on the gas pipeline 200. Figure 3 The schematic flowchart of the control method for the gas water heater according to an embodiment of the present invention is shown. As Figure 3 shown, the control method can include step S310 and step S320.

[0098] In step S310, according to the flow signal from the flow meter 120, the flow rate change amplitude of the water flow is determined.

[0099] In step S320, the booster pump 110 and the gas regulating valve 210 are controlled according to the flow rate change amplitude to control the gas water heater to activate the waterfall washing mode, where the booster pump 110 is used to connect to the water path 100. When the gas water heater is operating in the waterfall washing mode, the booster pump 110 makes the output water flow rate of the gas water heater greater than the rated water flow rate.

[0100] Figure 4 The schematic flowchart of the control method for the gas water heater according to another embodiment of the present invention is shown. As Figure 4As shown, after the gas water heater is turned on, when the water flow rate in its water circuit 100 is detected to be greater than or equal to 2.7 L / min and the water flow temperature at the water inlet is less than or equal to 43 degrees Celsius, the water heater ignites and heats up. The water flow rate is detected at a preset frequency, and when the water flow rate enters the preset flow rate range, the first timing operation starts. The maximum timing duration of the first timing operation is the third preset time, such as 5 seconds. If the water flow rate remains within the preset flow rate range within 5 seconds, it can continue to judge whether to start the waterfall washing mode. When the decrease amplitude of the water flow rate is greater than or equal to the first amplitude threshold of 1.5 L / min, it enters the standby state of the waterfall washing function and starts the second timing operation. The maximum timing duration of the second timing operation is 120 seconds. Only when the increase amplitude of the flow rate is detected to be greater than or equal to the second amplitude threshold within 120 seconds, the third timing operation starts. The maximum timing duration of the third timing operation is the second preset time, such as 5 seconds. Only when 1 time of flow rate increase, 1 time of flow rate decrease, and 1 time of flow rate increase are sequentially detected within the second preset time, and the flow rate decrease amplitude is greater than or equal to the first amplitude threshold of 1.5 L / min, and the flow rate increase amplitude is greater than or equal to the second amplitude threshold of 1.5 L / min, the subsequent control makes the booster pump 110 and the gas control valve 210 enter the waterfall washing mode. The water flow rate in the water circuit 100 is detected at a preset frequency. If the water flow rate is within the first flow rate range, the booster pump 110 is turned on, otherwise, vice versa. After the booster pump 110 is turned on, the water heater starts the fourth timing operation. When the timing duration of the fourth timing operation reaches the first preset duration, such as 20 seconds, the water heater saves the inlet water temperature T3 at 20 seconds. Based on the inlet water temperature T3, it is judged whether the temperature of the water flow under the rated heat load can reach the desired temperature. If it can reach the desired temperature, the gas control valve 210 is controlled to heat at a rate not greater than the rated heat load. If it cannot reach the desired temperature, the maximum current limit of the gas control valve 210 is increased, that is, the gas control valve 210 is controlled to work in the first working condition, and the fan is controlled for wind speed compensation according to the current value of the gas control valve 210 to suppress carbon monoxide emissions. The fifth timing operation starts when the gas control valve 210 works in the first working condition. The maximum timing duration of this fifth timing operation is the third preset duration, such as 5 minutes. Within 5 minutes, the following operations are performed. Detect the change in the water flow rate. If the water flow rate decreases and the decrease amplitude is greater than or equal to 2 L / min, the waterfall washing mode is exited. If there is no obvious change in the flow rate, but the current water temperature T1 at the water inlet ≥ T3 + 10°C or T1 ≥ T2 - 5°C, where T2 represents the desired temperature of the user, the waterfall washing mode is also exited. If the gas control valve 210 continuously operates in the first working condition for 5 minutes, the waterfall washing mode is also exited. After exiting the waterfall washing mode, the current upper limit of the gas control valve 210 can be restored. If the water flow rate is 0 L / min, the booster pump 110 is controlled to continue working for the fourth preset time, such as 5 seconds, and then stops.

[0101] Those of ordinary skill in the art can understand the relevant steps and beneficial effects of the above control method by reading the above descriptions related to the gas water heater. For the sake of brevity, they will not be elaborated here.

[0102] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by orientation words such as "front", "rear", "upper", "lower", "left", "right", "lateral", "vertical", "perpendicular", "horizontal" and "top", "bottom", etc. is usually based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description. Without contrary explanation, these orientation words do not indicate and imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the protection scope of the present invention; the orientation words "inner" and "outer" refer to the inside and outside relative to the contour of each component itself.

[0103] For the convenience of description, regional relative terms such as "above...", "over...", "on the upper surface of...", "upper" etc. can be used here to describe the regional positional relationship between one or more components or features shown in the drawings and other components or features. It should be understood that the regional relative terms not only include the orientation of the components described in the drawings, but also different orientations during use or operation. For example, if the components in the drawings are inverted as a whole, then the component "above other components or features" or "over other components or features" will include the situation where the component is "below other components or structures" or "under other components or structures". Thus, the exemplary term "above..." can include both the orientation of "above..." and "below...". In addition, these components or features can also be positioned at other different angles (such as rotated 90 degrees or other angles), and this document is intended to cover all such situations.

[0104] It should be noted that the terms used here are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should also be understood that when the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, components, assemblies and / or combinations thereof.

[0105] It should be noted that the terms "first", "second", etc. in the description, claims and above-mentioned drawings of the present application are used to distinguish similar objects and do not necessarily have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present application described here can be implemented in an order other than those illustrated or described here.

[0106] The present invention has been illustrated by the above embodiments. However, it should be understood that the above embodiments are only for the purpose of exemplification and illustration, and are not intended to limit the present invention to the scope of the described embodiments. In addition, those skilled in the art can understand that the present invention is not limited to the above embodiments, and more variations and modifications can be made according to the teachings of the present invention, and these variations and modifications all fall within the scope of protection required by the present invention. The scope of protection of the present invention is defined by the appended claims and their equivalent scope.

Claims

1. A gas water heater, characterized in that, it includes: a water circuit; a flow meter disposed on the water circuit; a burner for heating the water flow in the water circuit; a gas pipeline for delivering gas to the burner, and a gas regulating valve is disposed on the gas pipeline; and a controller for determining the flow rate change range of the water flow according to the flow signal from the flow meter, and controlling a booster pump and the gas regulating valve according to the flow rate change range to control the gas water heater to turn on the waterfall washing mode, wherein the booster pump is used to connect to the water circuit, and when the gas water heater operates in the waterfall washing mode, the booster pump makes the output water flow rate of the gas water heater greater than the rated water flow rate.

2. The gas water heater according to claim 1, characterized in that, the controller controls the booster pump and the gas regulating valve according to the flow rate change range to control the gas water heater to turn on the waterfall washing mode, including performing the following operations: when it is determined that a first preset condition is satisfied according to the flow rate change range, controlling the gas regulating valve and the booster pump so that the outlet water temperature of the gas water heater is the desired temperature of the water flow and the output water flow rate is greater than the rated water flow rate to turn on the waterfall washing mode; wherein, the first preset condition includes: there are a first preset number of flow rate drops within a first preset time, and there is a flow rate rise after each flow rate drop, wherein, when each flow rate drops, the flow rate drop amplitude is greater than or equal to a first amplitude threshold, and when each flow rate rises, the flow rate rise amplitude is greater than or equal to a second amplitude threshold.

3. The gas water heater according to claim 2, characterized in that, the first preset condition further includes: the time interval between the occurrence time of the first flow rate rise and the occurrence time of the last flow rate drop is less than a second preset time, wherein the second preset time is less than the first preset time.

4. The gas water heater according to claim 2 or 3, characterized in that, the first preset condition further includes: before a first moment, the flow signal of the flow meter indicates that the water flow flows at a flow rate within a preset flow rate range for at least a third preset time, wherein the first moment is the starting moment of the first preset time.

5. The gas water heater according to any one of claims 1 to 3, characterized in that, the gas water heater further includes a first temperature sensor disposed at the water inlet of the water circuit and a second temperature sensor disposed at the water outlet of the water circuit, the first temperature sensor is used to detect the water flow temperature at the water inlet of the water circuit, and the second temperature sensor is used to detect the water flow temperature at the water outlet of the water circuit; the controller controls the booster pump and the gas regulating valve according to the flow rate change range to control the gas water heater to turn on the waterfall washing mode, including performing the following operations: when it is determined that a first preset condition is satisfied according to the flow rate change range, controlling the booster pump to boost the water flow in the water circuit at a first lift, and the first lift is greater than the rated lift of the booster pump. Calculate the heat required to heat the pressurized water flow from the current water temperature at the water inlet to the desired temperature of the water flow; Determine whether the rated heat load of the gas water heater can provide the required heat; In the case where the rated heat load is insufficient to provide the required heat, control the gas control valve to operate under the first working condition so that the water temperature at the water outlet reaches the desired temperature. When the gas control valve operates under the first working condition, the heat load of the gas water heater is greater than its rated heat load.

6. The gas water heater according to claim 5, wherein, the controller is further configured to, when the gas control valve operates under the first working condition, perform a fifth timing operation on the duration of the gas control valve operating under the first working condition; when the time counted by the fifth timing operation reaches the third preset duration, control the gas water heater to exit the waterfall washing mode.

7. The gas water heater according to any one of claims 1 to 3, wherein, the water circuit includes a water inlet and a water outlet, and the water inlet and the water outlet of the water circuit are respectively used to connect to the water outlet and the water inlet of the external circulation pipeline of the gas water heater, the controller is further configured to control the gas water heater to exit the waterfall washing mode, and for the case where the flow signal indicates that the flow rate of the water flow is 0 L / min after exiting the waterfall washing mode, control the booster pump to continue running for a fourth preset time and then stop working.

8. The gas water heater according to claim 7, wherein, the gas water heater further includes a first temperature sensor disposed at the water inlet of the water circuit for detecting the water temperature of the water inlet of the water circuit, the controller is further configured to: when the gas water heater operates in the waterfall washing mode, perform a fourth timing operation on the duration of the gas water heater operating in the waterfall washing mode; when the time counted by the fourth timing operation reaches the first preset duration, store the detected water temperature of the water inlet; calculate the temperature sum of the stored water temperature of the water inlet and the first preset temperature; determine whether the current water temperature of the water inlet is greater than or equal to the temperature sum; in the case where the current water temperature of the water inlet is greater than or equal to the temperature sum, control the gas water heater to exit the waterfall washing mode.

9. The gas water heater according to claim 7, wherein, the gas water heater further includes a first temperature sensor disposed at the water inlet of the water circuit for detecting the water temperature of the water inlet of the water circuit, the controller is further configured to: when the gas water heater operates in the waterfall washing mode, calculate the temperature difference between the desired temperature of the water flow and the second preset temperature; determine whether the current water temperature of the water inlet is greater than or equal to the temperature difference; in the case where the current water temperature of the water inlet is greater than or equal to the temperature difference, control the gas water heater to exit the waterfall washing mode.

10. The gas water heater according to any one of claims 1 to 3, wherein, the controller is further configured to, When the gas water heater operates in the waterfall washing mode, when the flow rate decrease amplitude is greater than or equal to the third amplitude threshold, control the gas water heater to exit the waterfall washing mode.

11. A control method for a gas water heater, characterized in that, the gas water heater includes: a water circuit, a flow meter arranged on the water circuit, a burner for heating the water flow in the water circuit, a gas pipeline for delivering gas to the burner, and a gas regulating valve arranged on the gas pipeline; the control method includes: determining the flow rate change amplitude of the water flow according to the flow rate signal from the flow meter; controlling the booster pump and the gas regulating valve according to the flow rate change amplitude to control the gas water heater to turn on the waterfall washing mode, wherein the booster pump is used to connect to the water circuit, and when the gas water heater operates in the waterfall washing mode, the booster pump makes the output water flow rate of the gas water heater greater than the rated water flow rate.

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